Abstract: There is provided an optical film comprising: a multilayer base material film comprising an a-layer composed of a resin material (a) having a flexural modulus of 3 GPa to 4 GPa and a b-layer composed of a resin material (b) having a flexural modulus lower than the flexural modulus of the resin material (a), at least one of outer surfaces of the base material film being roughened by an emboss process or a blast process; and a functional layer, such as a hard coat layer and an anti-reflective layer, laminated on the roughened surface of the base material film. The optical film is used as a protective film for a liquid crystal display element, such as a polarizing plate.

Abstract: A protective film for polarizing plates comprises an antireflection layer (reflectance?0.5% at 550 nm) having high refractivity layers and low refractivity layers alternately laminated on a thermoplastic film (photoelastic coefficient?9.0×10?12 Pa?1, saturated water absorption<0.05% by weight) and has 0.3 or smaller standard deviation of S, which is obtained by obtaining a reflectance R(?) at a wavelength ? while ? is increased from 380 to 780 nm by an increment ?? of 1 nm, calculating S: S = ? ? = 380 780 ? ? ? ? ? · R ? ( ? ) ( 1 ) and calculating the standard deviation at 10 points randomly selected within 100 cm2 on the surface of the film. When the film is disposed on the surface of the visual side of a display device such as a liquid crystal display device, the film prevents reflection and suppresses fluctuation in distributions of luminance and color difference due to the uniform spectral reflectance within the surface of the film.

Abstract: A protective film for polarizing plate having a substrate film of a resin material and, laminated on at least one surface thereof directly or via another layer, an antireflection layer, characterized in that the substrate film has a photoelastic coefficient of less than 9×10?12 Pa?1 and a saturated water-absorbing percentage of less than 0.05%, and the resin material constituting the substrate film exhibits a warpage percentage of 1% or less when the film having an average thickness of 50 ?m and a dimension of 100 mm×100 mm is allowed to stand at 60° C. and a humidity of 95% for 500 hours is below 1%; a method for preparing the protective film for polarizing plate; a polarizing plate with antireflection function comprising the protective film and a polarizing plate laminated thereon; and an optical article having the polarizing plate with antireflection function.

Abstract: A protective film for polarizing plates comprises an antireflection layer (reflectance?0.5% at 550 nm) having high refractivity layers and low refractivity layers alternately laminated on a thermoplastic film (photoelastic coefficient?9.0×10?12 Pa?1, saturated water absorption<0.05% by weight) and has 0.3 or smaller standard deviation of S, which is obtained by obtaining a reflectance R(?) at a wavelength ? while ? is increased from 380 to 780 nm by an increment ?? of 1 nm, calculating S: S = ? ? = 380 780 ? ? ? ? ? ? · R ? ( ? ) ( 1 ) and calculating the standard deviation at 10 points randomly selected within 100 cm2 on the surface of the film. When the film is disposed on the surface of the visual side of a display device such as a liquid crystal display device, the film prevents reflection and suppresses fluctuation in distributions of luminance and color difference due to the uniform spectral reflectance within the surface of the film.